Fluid-brake.



0. LAUBEbZ.

FLUID BRAKE.

APPLICATION FILED 001229, 1908.

Patented Apr. 4, 1911.

rains rat ENT GFFICE QTTD LfiUBER, 0F ESSEN-ON-THE-RUHR, GERMANY, ASSIGNOR '10 FRIED. KRUPP I I EKTIENGESELLSCHAFT, OF ESSEIil-ON-THE-RUHR, GERMANY.

FLUID-BRAKE.

Specification of Letters Patent.

Patented Apr. 4, 1911.

To whom 'it may concern:

Be it known that I, OTTO LA'UBER, a sub jcct of the Emperor of Germany, and a resident of Essen on the Ruhr, Germany, have invented certain new and useful Improvements in Fluid-Brakes, of which the following is a specification.

The present invention relates to those typeset fluid-brakes for guns, in which the piston is provided with a part which is rotatahie relatively to the piston-body and engages with a part that causes the relative rotation during the piston-movements corresponding to the recoil and running out uuivcnients of the gun. This condition is met with, for example, in fluid-brakes wher-in throttling is effected by extending the -pass through both the rotating and a nonrotating-part of the brake, and gradually varying the by-pass, by the relative movement of the rotary part; such relative rotary movement being effected, for example, by having a projection on the rotatable part engage in a curved guide-groove in the brakecylinder proper or in a guiderod secured centrally in the brake-cylinder. The conditions with which the present invention is concerned may also be encountered in that type wherein the by-pass formed through the non-rotating part of the piston, does not open directly into the fluid chamher, but into the internal groove in the cylinder or surface groove in the guidcu'od referred to, so that such groove must form a part of the by-pass, and which groove, by

' its inclination to the direction of the pistons movement, gradually changes its degree of coincidence With the bypass in the piston, and thereby throttlesthe flow of liquid. In this latter type, a portion of the piston projects into the groove to close it against escape of fluid around the piston and since this groove in which the projection travels, is inclined to the direction in which the piston travels, the projection" is necessarily carried by a rotatable part of the piston. .lneaoh of the types mentioned, the projection slides along the walls of the guide-groove during the relative longitudinal movement of the piston and the brake cylinder.

The rotatable piston-part, even though exposed to fluid pressure only to the extent the z ejections er aging: in the guide grcoveawil be pressedfdurina' the entire braking movement, with great force against its counterbearing on the piston or piston rod. "his produces great friction between the contacting surfaces of the rotatable piston-part and its resisting bearing, with theefiect, among others, of causing the rotatable piston-part to offer large resistance to its rotation by the projections sliding in the guide-grooves. The projections of the rotatable piston-part will, therefore, likewise be pressed with considerable force against the appurtenant walls of the guidegroovcs and. considerable friction is, therefore, also produced between these parts of the fluid-brake.

The combined friction on the piston and in the guide-grooves is not undesirable as regards the action of the brake, as the friction increases the braking resistance in a welcome manner. Furthermore,there would be no reason for decreasing the friction because it causes wear of the rotatable pistonpart and its resisting bearing, as there is no objection to making the contacting surfaces of these parts so great that the wear on the surfaces remains within permissible limits. However, the case is different with the projections of the rotatable piston-part and their guide-grooves since the contacting surfaces of these parts must be comparatively small because the guide-grooves generally have small depth. In fact, the friction betwcen'these parts may cause the contacting surfaces to become Worn to such an extent that intermediate spaces are produced between the projections of the rotatable piston-part and their guide-grooves. These intermediatespaces remain open throughout the braking path and in an undesirable man ner increase the passages proper for controlling the flow of the fluid. In case of great wear, these intermediate siaces may have the efiect that the forces e ecting the recoil and return to battery do not become entirely absorbed, thus causing a shock to take place at the end of the recoil or the return movement. The enlargement of the passages which is caused by wear is especially disadvantageous in brakes with variable length of recoil because, when the brake is adjusted to a short recoil, the moving parts do not come to a stand-still until the openings for the circulation of fluid from one side of thepiston to the other are err-- tirely closed. If, for structural reasons, the

projections of the rotatable piston-part must be very narrow, the friction between the rotary part and the piston may even cause complete destruction of the projections.

The object of the present invention is to remove the drawbacks pointed out in the foregoing. 'This object is attained by'interposing anti friction means, such for instance as a circular row of balls or the like, between the rotatablepiston-part and at least that surface which acts as. resisting bearing for the rotatable part during recoil.

In the accompanying drawing, the invention is en'ibodied under conditions which render it effective during recoil, by way of example; the invention being applied for purposes of illustration to the fluid-brake forming the subject matter of the copending application of Otto Lauber and Norbert Koch, filed April 30, 1907, Serial No. 371,078, wherein the braking fluid flows from the fluid chamber on one side of the piston through a passageway formed in the nonrotating part of the piston.

Figure l is a longitudinal section through the piston and a part of the ln'ahc-i-ytinder; Fig. 2 is a section on line Fig. l, loot;- ing from the right; Fig. 3 a section on line 33, Fig. 1, looking from the left, and Fig. 4 is a detail of the piston.

i In the construction of recoil brake selec'ted for illustrating my invention, A rcp resents a brake-cylinder, and 13 represents the piston fitted in said cylinder. The piston B moves rearward in the direction of the arrow 0;, when the gun recoils, so that fluid in the rear chamber must escape past the piston, to the front chamber. When the gun returns to battery, the flow is reversed, passing from the forward chamber to the rear chamber. To permit such flow, yet restrict it sntlicicntly to impose necessary resistance to recoil, the piston B is constructed with ducts b In order to throttle the fluid passing through these duets, grooves a, a,

are provided in the inner wall of the cyl inder, and the ducts are made to open'into these grooves, and through-them communicate with the forward chamber, and said grooves are inclined to the'paths in which the ends of the ducts reciprocate, so that during recoil, said grooves gradually. move out of coincidence with the ducts and gradually reduce the sectional area of the outlets until the end of the groove is passed by the piston fwhen all flow will be cut off and the gun-barrel will be completely arrested. The presence of the grooves at, extending past the piston during recoil, necessitates closing such grooves as a means of communication from one sidc'of the piston to the other; otherwise the. ducts t), and their throttling means cou d not regulate the braking effect s is the purpose of the pro ections (.6 corresponding in transverse as described.

area to and fitting in the grooves a a But again, it has been seen that the grooves are inclined to the path of the piston, and the projections, therefore, must move relatively to the piston. This in turn has been provided for by forming the projections on a rotatable ring D, which is the particular part to which the present invention appertains. The ring D, which has projections (l engaging in spiral grooves in the brake cylinder A, is rotatably mounted in an annular. groove 6 in the piston B. The groove 6 is formed by a turned part on the side of the piston which is toward the piston-rod and by a. disk F rigidly secured to the piston. A circular row of balls E is interposed between the ring D and the annular face 5' of the piston B produced by the turning. The fluid passes from one side of the piston. to the other through pzissages b in the piston and through the grooves c in'the brakecylindcr. hen, after firing, the piston B rccoils in the direction of the arrow m (Fig. I), the n'ojcctions (Z slide along the walls of the spiral-grmvcs a? and turn the ring t) relative to the piston B. The fluid-pressure, which by reason of the movement of the piston is created on the piston-rod side of the brake-cylinder A, acts on the projections (Z of the ring D extending into" the grooves a and forces the ring against the annular face 6* of the piston B throughmhe medium of the balls E. Due to the balls E being inserted between the ring D and the piston B, the friction between the ring and its resisting bearing is effectively de-' creased and the wear on the walls of the grooves a and on the projections d which cause the ring to rotate is consequently equally decreased. j

Although the invention is chiefly adapted for use for the recoil, as the'forces acting during the recoil are considerably greater than those acting during the return movement, it is evident that the invention is not limited to such use. A row of balls might 'iery well be interposed also between the ring D and the disk l which serves as resisting bearing for the ring D during the return movement. It is apparent that rollers may be substituted for the balls E. I

Having thus described the invention, What is claimed as new therein and desired to be secured by Letters Patent is 1- 1. In a fluid brake, a brakc-cylinder, a piston having a part engaging a part of the brake-cylinder and rotatable relative to the piston, and anti-friction means for said piston-part.

2. In a fluid brake, a brake cylinder, a

iston having a part engaging a part of-the rake-cylinder and rotatable relative to the. piston, and anti-frict1on means interposed between said piston partand the piston.

3: A fluid brake for recoil-guns having a brake-cylinder, a piston provided with a part engaging a part of the brake-cylinder and rotatable relative to the piston, and having a surface forming a resisting bearing for said piston-part during recoil, and anti-friction means interposed between said pistonpart and said surface.

4-. In a fluid brake for recoil guns, a piston having a part adapted to rotate relative to the piston during recoil, and a ball bearing for said piston part.

5a In a fluid brake, a brake-cylinder, a. piston having a part engaging a part of the brake-cylinder and, rotatable relative to an other part or" theiston,- and anti-friction means between the said piston-parts.

6. A fluid brake for recoil-guns'having a brake-cylinder, a piston provided with a part engaging a part of the brake-cylinder and rotatable relative to the piston, said piston provided with a surface forming a resisting bearing for said piston part during recoil, and anti-friction means interposed between said piston-part and said surface.

The foregoing specification si ed at Barnien, Germany, this 10th day 01 September, 1908.

OTTO LAUBER.

In presence of- O'r'ro Komo, W. W. BRUNSWICK. 

